An instant messaging (IM) system is supposed to be a system that can send and receive Internet messages instantly. By using the IM system, a user can send text messages and transmit image data to another user, or perform communication activities with another user, such as audio conversations or video conversations.
Currently, in the IM system, a user can have a one-to-one or many-to-many chat and send IM messages to each other. The sent IM messages are arranged from top to bottom according to a sending time. Messages that are sent later are sequentially arranged behind messages that are sent earlier.
In an IM process, a user A sends a message and usually obtains a reply message from a user B after waiting for several seconds. However, when the user B replies to a previous message, the user A may be entering a message about another topic. In this way, if the user B wants to reply to a certain message that is sent earlier by the user A, reply messages can only be arranged behind according to a time sequence, which cannot make a timely feedback to a chat message of the user A pertinently. Reply messages are easily to be flooded by subsequent messages, which causes that the IM is not sufficiently instant as desired, and brings obstacles to instant communication between users.